Silver halide photographic emulsions used for electron beam recording

ABSTRACT

WHEREIN X represents an oxygen atom, a sulfur atom or N-H, X&#39;&#39; represents a sulfur atom, R1 and R2 represent each a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group or a 5 or 6-membered heterocyclic group having at least one nitrogen atom, or a condensed cyclic group thereof, R3 represents a hydrogen atom or a lower alkyl group, R4 represents a hydrogen atom, an alkyl group, an aryl group or a vinylmethyl group, and N REPRESENTS 0 OR 1.   Silver halide photographic emulsions used for electron beam recording which comprises at least one compound represented by formula (I) or (II), or salts thereof:

United States Patent 1 1 Matsuyama et al.

1 1 Nov. 25, 1975 1 SILVER HALIDE PHOTOGRAPHIC EMULSIONS USED FOR ELECTRON BEAM RECORDING [76] Inventors: Junichi Matsuyama; Yoshiyuki Nakazawa; Yasuharu Nakamura; Reiichi Ohi, all of Kanagawa, Japan; Tokiharu Kondo, deceased, late of Kanagawa, Japan, by Yoshiharu Kondo, legal representative [22] Filed: Jan. 15, 1974 [21] App]. No.: 433,609

Related US. Application Data [63] Continuation-impart of Ser. No, 214,460, Dec. 30,

1971, abandoned.

Primary Examiner-l Travis Brown Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT Silver halide photographic emulsions used for electron beam recording which comprises at least one com pound represented by formula (I) or (ll), or salts thereof:

a {3 R -(CH:CH) C:N-N-C-NHR (I) s 3 R -(CH:CH) -C:N-N-(|J:NH

wherein X represents an oxygen atom, a sulfur atom or NH,

X represents a sulfur atom,

R and R represent each a hydrogen atom, an alkyl group. a substituted alkyl group, an aryl group, a substituted aryl group or a 5 or 6-membered heterocyclic group having at least one nitrogen atom, or a condensed cyclic group thereof,

R represents a hydrogen atom or a lower alkyl group,

R represents a hydrogen atom, an alkyl group, an

aryl group or a vinylmethyl group, and

n represents 0 or 1.

10 Claims, N0 Drawings REFERENCE TO OTHER APPLICATIONS X'Ri (II) This application is a Conunuation-In-Part application 5 wherein of United States application Ser. No. 214,460, now abandoned, filed Dec. 30, 1971 of Junichi Matsuyama et al. entitled Silver Halide Photographic Emulsion Used for Electron Beam Recording.

BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to silver halide photographic emulsions, especially to silver halide photographic emulsions having a remarkably increased sensitivity to electron beams which is brought by adding certain specified compounds to silver halide photographic emulsions.

2. Description of the Prior Art In the preparation of silver halide photographic emulsions, chemical sensitizing processes that is, sulfur sensitization using thiosulfate, reduction sensitization using stannous chloride or hydrazine and noble metal sensitization using salts of noble metals such as gold, platinum and palladium have long been known as methods for increasing the sensitivity. However, it is insufficient to sensitize sensitive elements for electron beam recording by these known processes.

According to the electron beam recording process, it is possible to record at high resolution. However, in order to obtain images having high quality by this process, it is first necessary the silver halide particles of the sensitive element have a size as small as possible. However, since making the silver halide particles small in general causes deterioration of the sensitivity to electron beams development of a new sensitization process is required.

Further, it is necessary to decrease the surface electric charge of the sensitive element at electron beam exposure so as to obtain distinct images. Accordingly, it is necessary to decrease the dose of electron beams by increasing the speed of electron beam recording, and consequently sensitive element having a high sensitivity to electron beams is required.

SUMMARY OF THE INVENTION As the result of the various studies, the present inventors have discovered a way to remarkable increase the sensitivity to electron beams of photographic emulsions comprising a silver halide and, especially, fine grain silver halide crystals, preferably having a mean grain size by diameter no greater than 02p. particularly from 0.08 to 0.05 p.-

One object of the present invention is to provide silver halide photographic emulsions having a high sensitivity to electron beams.

This object has been attained by adding at least one compound represented by the following Formula (I) or (II), or a salt thereof to photographic emulsions comprising silver halide, and most especially fine grain silver halide crystals.

Formulae:

X represents an oxygen atom, sulfur atom or N-HX' represents a sulfur atom.

R, and R represents a hydrogen atom, an alkyl group (i.e., unsubstituted alkyl group and substituted alkyl group) such as a methyl group, an ethyl group or propyl group and an alkoxy carbonyl alkyl group (e.g., an ethoxycarbonylmethyl group), an aryl group (i.e., unsubstituted aryl group and substituted aryl group) such as a phenyl group, an aminophenyl group (e.g., a p-dimethylaminophenyl group, a p-aminophenyl group), a hydroxy phenyl group (e.g., an o-hydroxyphenyl group), an alkoxy phenyl group (e.g., a p-methoxyphenyl group), and a hydroxy (alkoxy) phenyl group (e.g., a 3 hydroxy 4 methoxyphenyl group), or a 5- or 6-membered heterocylic group containing at least one nitrogen atom or benzene or naphthalene nucleuscondensed heterocyclic group thereof such as a series of pyridine nucleus, a series of imidazole nucleus, a series of benzimidazole nucleus, a series of benzothiazole nucleus, or a series of naphthothiazole nucleus.

R represents a hydrogen atom or a lower alkyl group such as a methyl group, an ethyl group or a butyl group.

R, represents a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group of a hexadecyl group, an aryl group such as aphenyl group, or a vinylmethyl group.

n represents 0 or I.

A prefer carbon atom range of R or R is up to 4 while that of R or R, up to 18. The compound according to this invention may be salts of the compound of the formula (I) or (II) with acids capable of forming a salt with a nitrogen base of said compound of the formula, such as choloride, bromide iodide, sulfate, carbonate, nitrate, etc.

DETAILED DESCRIPTION OF THE INVENTION Typical compounds used in the present invention are shown below. However, these compounds are not intended to be [imitative thereof.

CH: NH

Compound 7 of the present invention can be prepared by the method described in Bailstein, vol 14, page 36. Other compounds can be prepared by the same method from corresponding carbonyl compounds and compounds having a primary amino group.

The silver halide photographic emulsions used in the present invention contains gelatin or other synthetic polymers as the binder, and one or more silver halides. As the silver halide, silver chloride, silver bromide, sil ver chlorobromide, silver bromoiodide and silver chlorobromoiodide may be used. Especially excellent results can be obtained from silver bromide and silver bromoiodide emulsions.

A sensitization effect is obtained by adding the compound of the present invention to silver halide photographic emulsions produced by any common method just before application. A similar effect is also obtained by adding the compounds at the step of forming silver halide crystals, the physical ripening step or the chemical ripening step.

The silver halide photographic emulsions may be sensitized as desired, by sulfur compounds and gold complex salts, or may be spectrally sensitized by sensitizing dyes such as cyanine dyes and merocyanine dyes.

In the silver halide photographic emulsions of the present invention, other chemical sensitizers, stabilizers, anti-fogging agents, matting agents, antistatic agents, hardening agents, surface active agents, plasticizers, development accelerators and, if desired, color formers, fluorescent brighting agents and toning agents can be used. These materials merely serve their art recognized functions.

The compounds used in the present invention are generally added as a solution dissolved in methanol or ethanol etc. The preferred amount of the compound used can vary in the range of l0 10 mol grams per l kg of the emulsion containing about 0.474 g mol A NO in accordance with the desired photographic and/or physical effect.

In the following examples, the present invention is explained in more detail.

EXAMPLES 1-17 A gelatin silver bromide emulsion having a 0.08 micron mean grain size by diameter was prepared by the simultaneous mixing method. After sulfur sensitization and gold sensitization, the sample was divided into two parts. One was used as is. To the other a compound shown in the Table l of the present invention was added. The emulsions were then applied to cellulose triacetate film base to prepare various identical samples (other than the presence or lack of the compounds of this invention).

After exposing stepwise in a range of 10' 10' coulombs/cm of current density at a 20 KV acceleration voltage by an electron beam application device, the samples were developed with using D-76 developer well known to one of ordinary skill in the art, by which characteristic curves were obtained.

In Table l, the common logarithms (Alog E) of the sensitization ratios for the case of adding the compound" of the present invention based on the case of not adding the compound of the present invention are shown as the sensitization ratio.

Table l-Continued Electron Beam sensitometry Example Com- Amount Sensitization Fog pound gram mol Kg ratio A log E of emulsion (fog 0.5)

2 2 0.4 X 10 0.50 0.05 3 3 0.4 X l 0.40 0.04 4 4 0.4 X 10" 0.90 0.03 5 5 2 X [0. 0.50 0.03 6 6 l X [0* 0.2 0.03 7 7 l x it) 0.30 0.03 8 8 l X l0" 0.20 0.03 9 9 l X I0"' 020 0.03 l0 l0 l X [0 0.30 003 ll ll 1 X I0 054 0.03 l2 12 l X 0.20 0.03 l3 13 l X 10" 0.35 0.03 l4 l4 1 X 10' 0.4 0.03 l5 15 l X 10* 0.2 0.03 16 16 l x 10 0.30 0.03 l7 17 l X 10' 0.30 0.03

As is clear from Table I, that the fog does not substantially increase and the sensitization ratio increases remarkably in the photographic emulsions of the present invention as compared with a photographic emulsion free from the compound.

What is claimed is:

1. A method for increasing the sensitivity of a silver halide photographic emulsion to electron beams by adding thereto, at least one compound represented by the following Formula (I) or (II), or the salts thereof, as set forth below:

wherein X represents a member selected from the group consisting of an oxygen atom, a sulfur atom and a =NH group; wherein X represents a sulfur atom; wherein R, and R each represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a heterocyclic group selected from the group consisting of a pyridine group, an imidazole group, a benzimidazole group, a benzothiazole group and a naphthothiazole group; wherein R represents a member selected from the group consisting of a hydrogen atom and a lower alkyl group; wherein R.. represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and a vinylmethyl group; and wherein n represents an integer of 0 or 1,

the silver halide in said silver halide photographic emulsion having a mean grain size, by diameter, of no greater than 0.2 microns.

2. The method of claim 1 wherein the silver halide grain has a mean grain size, by diameter, of from 0.8 to 0.05 microns.

3. The method of claim 1 wherein the silver halide is a member selected from the group consisting of silver bromide and silver bromoiodide.

4. The method of claim I wherein said compound is a member selected from the group consisting of 5. The method of claim 1 wherein said alkyl group is substituted with an alkoxy carbonyl substituent and wherein said aryl group is substituted by amino hydroxy, alkoxy or alkyl.

6. A process for recording electron beams which comprises imagewise exposing to electron beams a silver halide photographic emulsion containing at least one compound represented by Formula (I) or Formula (II) below, or the salts thereof:

1 Km. in:

wherein X represents a member selected from the group consisting of an oxygen atom, a sulfur atom and a ==NH group; wherein X represents a sulfur atom; wherein R and R each represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a heterocyclic group selected from the group consisting of a pyridine group, an imidazole group, a benzimidazole group, a benzothiazole group and a naphthothiazole group; wherein R represents a member selected from the group consisting of a hydrogen atom and a lower alkyl group; wherein R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and a vinylmethyl group; and wherein n represents an integer of 0 to l,

the silver halide in said silver halide photographic emulsion having a mean grain size, by diameter of no greater than 0.2 microns.

7. The method of claim 6, wherein the silver halide grain has a mean grain size, by diameter, of from 0.8 to

0.05 microns.

8. The method of claim 6, wherein the silver halide is a member selected from the group consisting of silver bromide and silver bromoiodide.

9. The method of claim 6, wherein said compound is a member selected from the group consisting of:

l SCielln 

1. A method for increasing the sensitivity of a silver halide photographic emulsion to electron beams by adding thereto, at least one compound represented by the following Formula (I) or (II), or the salts thereof, as set forth below:
 2. The method of claim 1 wherein the silver halide grain has a mean grain size, by diameter, of from 0.8 to 0.05 microns.
 3. The method of claim 1 wherein the silver halide is a member selected from the group consisting of silver bromide and silver bromoiodide.
 4. The method of claim 1 wherein said compound is a member selected from the group consisting of
 5. The method of claim 1 wherein said alkyl group is substituted with and alkoxy carbonyl alkyl substituent and wherein said aryl group is substituted with a member selected from the group consisting of an amino phenyl group, a hydroxy phenyl group, an alkoxy phenyl group, a hydroxy (alkoxy) phenyl group and an alkyl phenyl group.
 6. A PROCESS FOR RECORDING ELECTRON BEAMS WHICH COMPRISES IMAGEWISE EXPOSING TO ELECTRON BEAMS A SILVER HALIDE PHOTOGRAPHIC EMULSION CONTAINING AT LEAST ONE COMPOUND REPRESENTED BY FORMULA (I) OR FORMULA (II) BELOW, OR THE SALTS THEREOF:
 7. The method of claim 6, wherein the silver halide grain has a mean grain size, by diameter, of from 0.8 to 0.05 microns.
 8. The method of claim 6, wherein the silver halide is a member selected from the group consisting of silver bromide and silver bromoiodide.
 9. The method of claim 6, wherein said compound is a member selected from the group consisting of:
 10. The method of claim 6, wherein said alkyl group is substituted with an alkoxy carbonyl alkyl substituent and wherein said aryl group is substituted with a member selected from the group consisting of an amino phenyl group, a hydroxy phenyl group, an alkoxy phenyl group, a hydroxy (alkoxy) phenyl group and an alkyl phenyl group. 